So for ex above, we can use like:
String sReturnText=driver.findElement(By.id("SampleSpan1")).getAttribute("innerHTML");
System.out.println(sReturnText);

Because in the above example we are trying to get text from the control we can directly use getText method like below:
String sReturnText=driver.findElement(By.id("SampleSpan1")).getText();
System.out.println(sReturnText);

Solution 2: We can get the DOM properties be JavaScript
There might be situations you will be needing to run the JavaScript in your automation. To do this/cover the example follow below steps:
String sJScript = "return document.getElementById('SampleSpan1').innerHTML;";
String sReturnText = (String) ((JavascriptExecutor) driver).executeScript(sJScript);
System.out.println(sReturnText);